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Fully Accredited Legionella Testing Services

Legionella Testing

Legionella testing is essential to ensure proper compliance with current legislation, including ACOP L8, HSG274 and HTM 04-01 (Healthcare). It is crucial to limit the risk of occupants’ exposure to Legionella bacteria with proper Legionella risk assessment and management. We provide comprehensive Legionella testing services for hot and cold water systems for a range of commercial and residential clients.

We are fully accredited by the Legionella Control Association and also hold accreditations and memberships with CHAS, Constructionline and Safecontractor. Our highly experienced technicians are stationed throughout the country, enabling efficient, effective services. With a detailed reporting and guidance system completely tailored to your site, testing for Legionella has never been easier.

Get in touch with our specialist advisors today or fill out a contact form to book your Legionella testing services.

Request a quote





    What is Legionella Bacteria?

    Legionella bacteria is a type of bacteria found in water sources both natural and artificial. In premises where water systems are contaminated with the bacteria, exposure to this can happen through the spread of breathable water droplets. Exposure to Legionella bacteria in this way can lead to the development of Legionnaires’ disease, a severe form of pneumonia which can be fatal.

    A Legionella Risk Assessment is a legal requirement under the Health and Safety at Work Act in 1974 and is essential for the health and safety of all workers and occupants of your premises.

    Legionella bacteria

    Hot tub hydromassage pool

    Any recirculated system or hot and cold water system is at risk of Legionella bacteria growth. There are four key elements which cause this:

    1. Habitat: Showerheads, sprinkler hoses, taps, hot water cylinders, poor plumbing, and other system issues can allow Legionella bacteria to multiply rapidly.
    2. Food source: Food sources for Legionella bacteria include sediment, scale and other bacteria.
    3. Warm temperatures: The optimal temperature range for the growth of Legionella bacteria is 20-25 degrees celsius. 
    4. Aerosol release: Water contaminated with Legionella bacteria released as an aerosol poses a great risk.

    Water systems that are typically at high risk of Legionella include:

    • Spa pools
    • Hot tubs
    • Swimming pools
    • Dental apparatus
    • Showers
    • Healthcare Properties
    • Vehicle cleaning machines
    • Food manufacturing sites
    • Washing facilities
    • Industrial facilities like manufacturing sites

    Any building or site that includes the above will need regular risk assessments.

    A worker wearing a face mask while holding a clipboard

    How We Can Help With Legionella Testing

    We provide a comprehensive Legionella testing service as well as monitoring and control services. Our trusted technicians have helped our clients achieve Legionella compliance safely and effectively.

    As well as Legionella water testing, we offer a range of accredited services which help you get your company or property to Legionella compliance:

    • Legionella Risk Assessments 

    We are trusted providers of one of the most comprehensive risk assessment services. These are completed onsite by our highly experienced technicians who expertly assess the risks across your hot and cold water systems. We provide a fully detailed report with schematic drawings and recommended actions across the site.

    • Legionella Water Monitoring

    This is typically conducted monthly to ensure the scheme for controlling risks of Legionella is properly completed. All results and instances of non-conformance are recorded on our online system which then sends you monthly reports with test results and actions required.

    All our water testing for Legionella is completed in line with HSG274 and Acop L8.

    What to Expect From Our Onsite Legionella Testing Services

    We complete onsite Legionella water testing on a monthly, quarterly, or six-monthly basis:

    1. Our trained technicians have approved UKAS calibrated thermometer test kits which are used to take the water temperatures across your site.
    1. All temperature and inspection results are then recorded on our online system and inputted onto a mobile application.
    1. Our office reviews these results and adds any comments.
    1. We then send you these detailed reports with quotes for the recommended actions included.

    We pride ourselves on our bespoke reporting service that includes detailed guidance you won’t find with other Legionella testing companies. We work collaboratively with our clients to ensure you feel fully supported in your journey to Legionella compliance.

    Drinking Water Quality Test For Legionella

    Legionella Testing Cost

    The cost of onsite Legionella testing services from us varies depending on your site and the complexity of its water systems. With Guardian Hygiene Services, you get a comprehensive service that is tailored completely to your needs. Included in the costs is a bespoke reporting system that offers detailed guidance and aftercare which is often not included with other Legionella testing companies.

    A woman wearing a face mask and cover

    If you do not complete monthly checks as part of a written control scheme in-house, we recommend our monthly water monitoring services. You should also flush your system weekly and record this each time.

    If you already complete checks in-house and record these correctly, then we recommend six-monthly checks to ensure the results are correct and that all inspections are being completed properly.

    Please see the below extract from HSG 274 part 2 as an example of a written control scheme for Legionella testing:

    ServiceAction to takeFrequency
    CalorifiersInspect calorifier internally by removing the inspection hatch or using a boroscope and clean by draining the vessel. The frequency of inspection and cleaning should be subject to the findings and increased or decreased based on conditions recordedAnnually, or as indicated by the rate of fouling
    Where there is no inspection hatch, purge any debris in the base of the calorifier to a suitable drain Collect the initial flush from the base of hot water heaters to inspect clarity, quantity of debris, and temperatureAnnually, but may be
    increased as indicated by the
    risk assessment or result of
    inspection findings
    Check calorifier flow temperatures (thermostat settings should modulate as close to 60 °C as practicable without going below 60 °C) Check calorifier return temperatures (not below 50 °C).Monthly
    Hot water servicesFor non-circulating systems: take temperatures at sentinel points (nearest outlet, furthest outlet and long branches to outlets) to confirm they are at a minimum of 50 °C within one minute (55 °C in healthcare premises)Monthly
    For circulating systems: take temperatures at return legs of principal loops (sentinel points) to confirm they are at a minimum of 50 °C (55 °C in healthcare premises). Temperature measurements may be taken on the surface of metallic pipeworkMonthly
    For circulating systems: take temperatures at return legs of subordinate loops, temperature measurements can be taken on the surface of pipes, but where this is not practicable, the temperature of water from the last outlet on each loop may be measured and this should be greater than 50 °C within one minute of running (55 °C in healthcare premises). If the temperature rise is slow, it should be confirmed that the outlet is on a long leg and not that the flow and return has failed in that local areaQuarterly (ideally on a rolling monthly rota)
    All HWS systems: take temperatures at a representative selection of other points (intermediate outlets of single pipe systems and tertiary loops in circulating systems) to confirm they are at a minimum of 50 °C (55 °C in healthcare premises) to create a temperature profile of the whole system over a defined time periodRepresentative selection of other sentinel outlets considered on a rotational basis to ensure the whole system is reaching satisfactory temperatures for legionella control
    POU water heaters (no greater than 15 litres)Check water temperatures to confirm the heater operates at 50–60 °C (55 °C in healthcare premises) or check the installation has a high turnoverMonthly–six monthly, or as indicated by the risk assessment
    Combination water heatersInspect the integral cold water header tanks as part of the cold water storage tank inspection regime, clean and disinfect as necessary. If evidence shows that the unit regularly overflows hot water into the integral cold water header tank, instigate a temperature monitoring regime to determine the frequency and take precautionary measures as determined by the findings of this monitoring regimeAnnually
    Check water temperatures at an outlet to confirm the heater operates at 50–60 °CMonthly
    Cold water tanksInspect cold water storage tanks and carry out remedial work where necessaryAnnually
    Check the tank water temperature remote from the ball valve and the incoming mains temperature. Record the maximum temperatures of the stored and supply water recorded by fixed maximum/minimum thermometers where fittedAnnually (Summer) or as indicated by the temperature profiling
    Cold water servicesCheck temperatures at sentinel taps (typically those nearest to and furthest from the cold tank, but may also include other key locations on long branches to zones or floor levels). These outlets should be below 20 °C within two minutes of running the cold tap. To identify any local heat gain, which might not be apparent after one minute, observe the thermometer reading during flushingMonthly
    Take temperatures at a representative selection of other points to confirm they are below 20 °C to create a temperature profile of the whole system over a defined time period. Peak temperatures or any temperatures that are slow to fall should be an indicator of a localised problemRepresentative selection of other sentinel outlets considered on a rotational basis to ensure the whole system is reaching satisfactory temperatures for legionella control
    Check thermal insulation to ensure it is intact and consider weatherproofing where components are exposed to the outdoor environmentAnnually
    Showers and spray tapsDismantle, clean and descale removable parts, heads, inserts and hoses where fittedQuarterly or as indicated by the rate of fouling or other risk factors, eg areas with high risk patients
    POU filtersRecord the service start date and lifespan or end date and replace filters as recommended by the manufacturer (0.2 µm membrane POU filters should be used primarily as a temporary control measure while a permanent safe engineering solution is developed, although long-term use of such filters may be needed in some healthcare situations)According to manufacturer’s guidelines
    Base exchange softenersVisually check the salt levels and top up salt, if required. Undertake a hardness check to confirm operation of the softenerWeekly, but depends on the size of the vessel and the rate of salt consumption
    Service and disinfectAnnually, or according to manufacturer’s guidelines
    Multiple use filtersBackwash and regenerate as specified by the manufacturerAccording to manufacturer’s guidelines
    Infrequently used outletsConsideration should be given to removing infrequently used showers, taps and any associated equipment that uses water. If removed, any redundant supply pipework should be cut back as far as possible to a common supply (eg to the recirculating pipework or the pipework supplying a more frequently used upstream fitting) but preferably by removing the feeding ‘T’ Infrequently used equipment within a water system (ie not used for a period equal to or greater than seven days) should be included on the flushing regime Flush the outlets until the temperature at the outlet stabilises and is comparable to supply water and purge to drain Regularly use the outlets to minimise the risk from microbial growth in the peripheral parts of the water system, sustain and log this procedure once started For high risk populations, eg healthcare and care homes, more frequent flushing may be required as indicated by the risk assessmentWeekly, or as indicated by the risk assessment
    TMVsRisk assess whether the TMV fitting is required, and if not, remove Where needed, inspect, clean, descale and disinfect any strainers or filters associated with TMVs To maintain protection against scald risk, TMVs require regular routine maintenance carried out by competent persons in accordance with the manufacturer’s instructions. There is further information in paragraphs 2.152– 2.168Annually or on a frequency defined by the risk assessment, taking account of any manufacturer’s recommendations
    Expansion vesselsWhere practical, flush through and purge to drain. Bladders should be changed according to the manufacturer’s guidelines or as indicated by the risk assessmenMonthly–six monthly, as indicated by the risk assessment
    Legionella Services

    What Property Types and Business Sectors Do We Cover?

    We have become one of the most trusted Legionella risk assessment providers for a number of clients. 

    The business sectors we cover include:

    • Hospitals
    • Care Homes
    • Funeral Homes
    • Landlords in charge of multiple rental properties
    • Retail
    • Restaurants
    • Hairdressers
    • Dental Practices
    • Health Clubs
    • Sports Centres
    • Local Authority
    • National Trust
    • Universities
    • Schools
    • Hotels
    • Leisure Clubs
    • Factories, including food production
    • All commercial company properties

    Legionella Risk Assessments Cost

    The size of your site and the complexity of its water systems will affect the cost of your risk assessment for Legionella. Whatever the needs of your property are, we can work with you to accommodate them. 

    Book Our Legionella Testing Services Today to Ensure Legal Compliance

    When it comes to Legionella, controlling the risks of exposure with regular water testing is vital. With our fully accredited range of services backed up by years of skill and experience, you can ensure safety and peace of mind for all workers, owners and tenants of your premises.

    Our technicians are based across the country, enabling quick response times and an outstanding level of customer service. To book your accredited Legionella testing services, get in touch with our specialists today.

    Request a quote